When it came to moral "reasoning," we like to think our views on right and wrong are rational, but ultimately they are grounded in emotion. Philosophers have argued over this claim for a quarter of a millennium without resolution. Time"s up! Now scientists armed with brain scanners are stepping in to settle the matter. Though reason can shape moral judgment, emotion is often decisive. Harvard psychologist Joshua Greene does brain scans of people as they ponder the so-called trolley problem. Suppose a trolley is rolling down the track toward five people who will die unless you pull a lever that diverts it onto another track—where, unfortunately, lies one person who will die instead. An easy call, most people say: minimizing the loss of life—a "utilitarian" goal, as philosophers put it—is the right thing to do. But suppose the only way to save the five people is to push someone else onto the track—a bystander whose body will bring the trolley to a halt before it hits the others. It"s still a one-for-five swap, and you still initiate the action that dooms the one—but now you are more directly involved; most peoplesay it would be wrong to do this deal.Why? According toGreene"s brain scans,the second scenario more thoroughly excites parts of the brain linked to emotion than does the lever-pulling scenario. Apparently the intuitive aversion to giving someone a deadly push is stronger than the aversion to a deadly lever pull. Further studies suggest that in both cases the emotional aversion competes for control with more rational parts of the brain. In the second scenario the emotions are usually strong enough to win. And when they lose, it is only after a tough wrestling match. The few people who approve of pushing an innocent man onto the tracks take longer to reach their decision. So too with people who approve of smothering a crying baby rather than catching the attention of enemy troops who would then kill the baby along with other innocents. Princeton philosopher Peter Singer argues that we should re-examine our moral intuitions and ask whether that logic merits respect in the first place. Why obey moral impulses that evolved to serve the "selfish gene"—such as sympathy that moves toward kin and friends? Why not worry more about people an ocean away whose suffering we could cheaply alleviate? Isn"t it better to save 10 starving African babies than to keep your 90-year-old father on life support? Singer"s radically utilitarian brand of moral philosophy has its work cut out for it. In the absence of arduous cranial wrestling matches, reason may indeed be "slave of the passions."
单选题
From the first two paragraphs, we can learn that